When transferring business entity data between the tiers, there is a need to create “data transformation objects” that transport object information across the network (if not invoked directly). DTOs also allow to separate layers and expose only those data that we will use (encapsulation). It is especially useful when using restful services.

Diagram below shows the typical n-tier architecture using presentation components and entities.

Diagram 1. Presentation model components and entities in multi tier application (please refer to “Microsoft Application Architecture Guide, 2nd Edition” book for more details).

Please note that using DTOs may incur some performance lost as the objects need to be mapped and transformed between the layes/tiers. Solution for that could be executing batch commands at once sending final results as combined object to avoid round trips within the network.

If your tiers are located within your local network it is advisable to use TCP protocol(more efficient) otherwise use HTTP/HTTPS when transferring data across the public network.

Artykuł Using presentation model components and entities in ntier architecture pochodzi z serwisu Proxmedia.

Further interaction is shown on the next diagram:

Process chain for the above diagrams depicts following image:

ITIL itself, can be described as follows:

Finally, the last diagram shows how PRINCE2 relates to Architecture within its operational level:

For more information, please check following video:

Artykuł TOGAF vs COBIT, PRINCE2 and ITIL – Webinar pochodzi z serwisu Proxmedia.